In recent years, in the field of, for example, wire harnesses such as those for automobiles, aluminum electric wires have been used to save weight and the like. Aluminum electric wires have a structure in which their core wires are made of, for example, stranded wires obtained by twisting a plurality of aluminum bar wires together, and are covered with an insulating cover. If the aluminum electric wires are bundled into harnesses, terminals are typically connected to ends of the electric wires. Specifically, the insulating cover of an aluminum electric wire is stripped at an end so that ends of the core wires are exposed, and a wire barrel (electric wire connection portion) of the terminal is crimped and connected to the exposed ends of the core wires, and an insulation barrel provided rearward of the wire barrel is crimped to the remaining end of the insulating cover.
JP2011-192530A is an example of background prior art.